Digital logic circuits are widely used in electronic systems. These systems may be very simple systems, such as individual logic gates that are used for simple control circuits. They may also include moderately complex systems, such as integrated logic circuits that are used for controllers are embedded processors. These systems may also include processors that are much more complex and are used in powerful computing systems.
These digital electronic systems are typically designed primarily in terms of the logic functions that are performed by their various subsystems and components. In other words, the design of the system focuses on the logic that will be used by the system to handle input, output, control and other information. The logic design is based upon the use of logic gates, such as AND, OR, NAND, NOR, XOR and various other types of gates. While these gates are, from the perspective of the logic design, the basic building blocks of the hardware logic of the system, it is important to keep in mind that each of these gates typically comprises transistors and various other electronic components that are combined to form the logic gate.
The electronic components that form the gates of the digital logic require power to operate. In other words, the logic gates are not simply passive devices that require no power to produce a desired output from a given input. Because of the increasing number of logic gates and corresponding electronic components in systems such as data processors, the amount of power that is required by the electronic components is increasingly a concern in the design of these systems. Accordingly, it is, as a general matter, always desirable to provide new ways to reduce the amount of power that is required by the system. Even a small power savings at the electronic component (sub-gate) level may translate to a large power savings at the system level because of the large number of electronic components within the system.